What is being measured?
Electric charge is distinct from electric current. Charge transferred depends on current and elapsed time when the corresponding relationship applies.
Ah and mAh measure charge, not energy. Wh conversion requires voltage.
Meaning of fC
Femtocoulombs uses the symbol fC in this library and measures electric charge. Under the stated reference convention, 1 fC = approximately 1e-15 C. This equivalence changes how a known value is written. It does not increase measurement accuracy or establish whether a measurement is appropriate to a real application.
Conversion method
Multiply the value by the source factor (1e-15), then divide by the target factor (1). The factor ratio expresses the same electric charge measurement in the other unit.
Worked example
For a known value of 10 fC, the reference conversion gives 1e-14 C. Converting that result back gives approximately 10 fC. This reverse check helps catch a reversed factor, but matching round-trip arithmetic alone does not independently verify a source definition.
Common reference values
| Input (fC) | Reference equivalent (C) |
|---|---|
| 1 | 1e-15 |
| 5 | 5e-15 |
| 10 | 1e-14 |
| 25 | 2.5e-14 |
| 50 | 5e-14 |
| 100 | 1e-13 |
Compare one fC with other units
| Target unit | Equivalent of 1 fC | Definition guide |
|---|---|---|
| Coulombs (C) | 1e-15 | Read definition |
| Millicoulombs (mC) | 1e-12 | Read definition |
| Microcoulombs (µC) | 1e-9 | Read definition |
| Nanocoulombs (nC) | 0.000001 | Read definition |
| Ampere hours (Ah) | 2.77777777778e-19 | Read definition |
| Milliampere hours (mAh) | 2.77777777778e-16 | Read definition |
| Picocoulombs (pC) | 0.001 | Read definition |
| Kilocoulombs (kC) | 1e-18 | Read definition |
Precision and common mistakes
- Keep the source and target quantity consistent. A matching symbol is not enough to establish a compatible definition.
- Record the original measurement precision. Showing twelve significant digits in a table does not make a rounded input more precise.
- Check symbol capitalization, prefixes and any regional convention in the source. Use the displayed unit definition rather than a similarly named unit.
- Factors involving repeating fractions or π use finite numerical precision. Round the final answer to the precision justified by your input.
Use a working converter
- Electric charge converter
- Femtocoulombs to Coulombs converter
- Femtocoulombs to Millicoulombs converter
- Femtocoulombs to Microcoulombs converter
- Femtocoulombs to Nanocoulombs converter
- Femtocoulombs to Ampere hours converter
Source and verification scope
Examples and tables are computed from the versioned unit definitions used by the linked converters. The source access dates appear below. Computandum is independent of the cited organizations; a citation does not mean that a publisher endorses this page or an actual project.